Hey guys, adjustments to FMU involve dialing it in with the vacuum signal disconnected at idle. This simulates WOT for FMU. While monitoring fuel pressure, the unit is dialed to a set point 48-55 psi.
There is an additional fine tune needle valve to adjust AFR at boost.
Pretty slick, but here’s is where I am at:
AFRs look really good (mid 12’s) until I drop vacuum and approach WOT. Then with boost the FMU takes over and even with full adjustment on this unit, it goes way rich.
As my boost goes up it drops to low tens, even occ high nines.
I researched the vortech website and they will traditionally recommend 10.8-11.1 AFR at max boost.
This is not a vortech unit but is this where you want to be with an FMU in general terms? It seems rich but maybe this is a cushion you need without better engine management ie shartuner.